Effect of seaweed extract and bradirhizobium inoculation on growth, nodulation and yield attributes of Cowpea (Vigna Unguiculata L Walp) under tunnel house and field conditions

Abstract

A 3-factorial agronomic experiment was carried out under field and tunnel house conditions to investigate the effect of seaweed extract and Bradyrhizobium inoculation on cowpea growth and performance. In both trials, treatment factors consisted of two cowpea varieties and three Seaweed extract levels (0:00, 1:500 and 1:100 v/v; extract to water ratio) applied at a rate of 2 L ha-1 with and without Bradyrizobium inoculation. Results showed that all measured growth and yield parameters were increased following increase in Seaweed extract concentration while seed inoculation proved superior to uninoculated treatments. Application of the extract resulted in approximately 10-20% increase in cowpea leaf chlorophyll content, 43-88% improvement in nodulation and 9.5 -29.9% grain yield increases. Similarly, cowpea seed inoculation resulted in 37-42% increase in leaf chlorophyll content over 200% increase in nodulation and up to 40% grain yield increases when compared to the uninoculated treatment. A synergistic effect of the application of seaweed extract in the presence of Bradyrhizobium inoculation was recorded in both the field and tunnel house experiments with significant effect on cowpea leaf chlorophyll content and nodulation. Such synergy promoted nodulation, better crop performance and increased grain yield.